No one's going to be impressed by "I watched a C section being performed in a hospital." Anyone can watch a C-section as well as more complex, full-length surgeries being performed on youtube. (Which would give a better view of what was happening anyway)
You need to put across what you gained from the experience itself. What did you learn? How did it enlighten you about the roles of doctors, and surgery as a speciality? How has it changed your expectations and perception of working in the medical field? What did you learn from being in a hectic hospital environment, witnessing the chaotic yet extremely precise and organized nature of surgery? What did you learn from witnessing the vital teamwork demonstrated by a surgical team performing an operation?
Don't rely on impressing the admission tutor by saying you watched a C section. What will impress them is knowing why you would want to watch it in the first place. Why you would be interested. What steps did you take and what were your reasons for seeking out the opportunity to watch the surgery? How has it influenced your decision to pursue a career in medicine?
That's what the person reading your personal statement is going to care about. Substance.